Question

A rope pulls on a metal box at an angle of 60.0° with a force of 255 N. The box moves horizontally for 15.0 m. How much work was done on the box?

Answer 1

The work done by the rope on the box is equal to:
$W=Fd \cos \theta$
where F is the force applied by the rope, d the  distance covered by the box and $\theta$ is the angle between the direction of the force and of the displacement.

Using the data of the problem: $F=255 N$, $d=15.0 m$ and $\theta = 60^{\circ}$, we find the work:
$W=(255 N)(15.0 m)(\cos 60^{\circ})=1912.5 J$